It did before, at least according to a growing number of scientists specializing in the evolution of the human brain.

When the hominid line split off from other apes about six million years ago, bipedalism and other physiological changes happened pretty quickly -- from the neck down. But it wasn't until about two-and-a-half million years ago that hominid brains started to really grow, from Homo habilis' ~500-600cc brains (chimps are a bit less than 400cc) to Homo sapiens' ~1400cc brains. The trigger for this cerebral explosion appears to be a period in which the global climate started going through a series of abrupt changes. Ice ages and warming periods flip-flopped, making it difficult for species relying upon particular environmental niches or conditions to survive. The species that did best were the ones able to evolve ways of dealing with rapid environmental changes; in the case of hominids, they got smarter.

We now face another round of climate disruptions, and this time it's happening far faster than the natural processes of past eras. Other environmental hazards abound, as well, threatening to make a bad situation worse. Will all of this lead, once again, to a new phase in human intelligence?

The BBC reports of recent findings confirming that the region in Africa home to important steps in the evolution of humans went through dramatic shifts in climate from 3 million years ago to 1 million years ago. Massive lakes formed and dried up at least three times in the period, indicating large shifts in moisture and temperature happening in a geologically short period (although far, far more gradually than the climate disruption underway today).

Dr. William Calvin, neurophysiologist at the University of Washington, has long argued that there's a connection between the evolution of intelligence and climate shifts. Calvin's 2002 book, A Brain For All Seasons,spelled out his argument in great -- and, to many, quite convincing -- detail. The book is still in print, but Calvin has also made the contents available as HTML here. Be forewarned; Calvin is apparently a great fan of Internet Explorer, and there are some weird rendering artifacts in Firefox and Safari on some pages.

Calvin's argument is interesting, in that the primary connection he draws between climate changes and brain evolution is that the environmental pressures led to a great need for cooperation between hominid individuals, and that increased cooperation required better communication abilities. Tools, fire, skinning animals for furs or to make skins to hold water -- all very useful, but what really let us survive was our ability to tell each other where to find food resources, how to make the tools and skins, plans for cooperatively bringing down larger prey or fending off attacks from predators, even ideas about what tomorrow might bring.

Would similar environmental pressures have the same result today?

Claims that humans are no longer subject to evolution aren't hard to find, and the more rational versions make the claim that natural selection pressures have largely been rendered moot through social cooperation and helpful technology. This may be so, and while something leading to the collapse of civilization may well lead to the resurgence of natural selection, it's reasonable to argue that society and technology allow us to expand "survival of the fittest" to a very large portion of the human population.

But if you think about the claims from Calvin and others that environmental pressure forced us to improve our communication skills and cooperative tools, it's not as clear that we're no longer subject to evolution.

It's certain that the potential disasters such as global warming-triggered climate disruption, oil depletion, and pandemics such as human-transmissible H5N1 are making us rely more and more on effective tools of knowledge acquisition and communication. Sites like the Avian Flu wiki, the Oil Drum, and yes, even WorldChanging and myriad others we talk about here on a daily basis are important parts of a structure for understanding and learning how to deal with disruptive changes. Sensors, computers and networks allow us better ways to recognize, analyze and tell others about changes to the world around us. Simulations and modeling can aid in seeing future opportunities and risks, and databases help to make sure that we don't forget them. Moreover, all of these tools are developing and advancing at a rate far exceeding biological evolution.

In short, we are improving our ability to communicate and cooperate, we're just not doing it biologically.

I do think that climate change and the various other big challenges we will face in the months and years to come will make us smarter, even if our cranial size is unaffected. We will be forced to develop better ways of understanding what's happening, looking for options, and cooperating on solutions. The ability to communicate clearly and completely will again be a species survival trait.

This is no reason to welcome global warming (or peak oil, or H5N1 pandemics...). It is, however, another reason for hope. Hominids, of which humans are simply the latest version, have demonstrated a remarkable ability to respond to environmental pressures, and each successive threat has left us smarter, more cooperative, and better able to handle what comes next. This time around, the dangers are potentially the worst the hominid line has ever faced -- but we also have the greatest resources the hominid line has ever possessed. This time, we may even be smart enough to head off disaster before it hits.

Climate change is only going to lead to increased intelligence if it causes greater prevalence of whatever alleles make people smart. When you consider that it only takes a few tens of thousands of scientists and perhaps a million engineers to do the mental heavy lifting and most everyone else just has to follow along, it seems just as likely that those who will "win" are going to be the followers of certain enlightened leaders and intelligence might have very little to do with it.

It's not hard to imagine that climate change 2.5 million years ago led to a jump on the intelligence chart. What I'd be more interested to hear about, though, is what the effect of the climate change had on the population. I suspect that the 1% of us who leave descendants in 100 generations may well leave smarter ones because of climate change, but it won't be much comfort to the people who starve or die of malaria in the meantime.

Posted by: dave cutler on 20 Aug 05

What David Said.

For climate change to increase our intelligence would require a big die-off and harsh selection for cleverness.

For our civilization, the big question is:

Will climate change make us wiser?

And perhaps: Which societal memes will be selected for over the next decades?

Posted by: Stefan Jones on 20 Aug 05

Not realy all it requires is a bunch of people trying to outsmart each other with death or dismemberment being the penalty for failure.

Posted by: wintermane on 20 Aug 05

Human culture is what's evolving right now - there are too few of us who die before becoming parents to have any sort of direction to human physical evolution for the foreseeable future. Will the challenges of the near term lead to improvements in culture that make us all work together better? I think it certainly is not a for-ordained consequence, but there's potential there, sure. In fact, one hope is that the internet (and some of the trends you point out) are going to contribute greatly to that needed cultural evolution for us. Not a moment too soon, and perhaps too late...

Whoa- no need to talk about mass deaths here. Even a 1% increase in reproduction of the smartest people over 1000 generations could have a significant impact.

Posted by: Daniel Haran on 20 Aug 05

Rapid evolution as a result of environmental change seems logical for organisms dependent on the environment. Since we have ceased to be individually linked to our environment this is no longer the case. There is a possible analogy which can be drawn that sustainable governments and organizations are tied to their environment, but I would cease to call this evolution, rather some other term which is less confusing like development.
However, a more interesting idea is that the changes we made on Earth will evolve another creature that can outguess and out-think environmental change as we did thousands of years ago, and this time the animal will have to be faster then us. Anyone noticed how smart crows are lately?

Crows have always been smart. They only seem smarter now because they have access to education in the form of discarded college textbooks.

Posted by: Stefan Jones on 20 Aug 05

The gradeschooler from the US who'd just learned about tsunamis in class saved her family and many of the people around them.

1% differential reproduction over 1000 generations might do it, but do you seriously think that this global warming business will still be a current problem 20,000 years (1000 generations) from now?

Really increasing individual intelligence with regard to the class of problems of which global warming is a member will require much more intelligence of the type used for quantitative analysis, plus fewer tendencies toward groupthink. Unfortunately, all the social pressures are going the other way.

I can envision maybe a few quite shallow perspectives from which this is true. Tim, I'll assume you're talking in a relative sense, in that we're linked but many steps removed thanks to our techno-social acheivements - technological buffers like food storage and social ones like the division of labour.

But as a statement in itself it seems revealingly symptomatic of our psychic disconnect, masquerading as perception of apparent physical disconnect.

My guess is that it's precisely the big environmental issues like climate change and resource depletion that are going to - gradually, suddenly, or both - force us to reconnect psychically, as a precondition for acting smarter within the physical systems that support us. Reconnecting psychically merely means acting from cultural, mental, possibly spiritual baselines that are in synch with the physical systems we're embedded in.

We're already smart enough to deal with climate change. Are we smart enough to change some ideas about ourselves that we cling to fervently? Some stories that our clever minds have created are threatened. Can our clever minds find better stories in time to change our actions? Time will tell.

many comments above talk about genetic change (which is conveniently external to our locus of control) over internal, self-change for learning and extending our developmental stages of intelligence.

A smart approach woud be to embrace lives of learning through novel experience, cultivating thoughtfulness, exchange, shared problem-solving, cross-cutting specialist knowledge, action-learning and of course, by being the change we want to see. Being individually responsible.

Also as many evolution thinkers are discussing today, learning to think original thoughts, doubting our own doubts and learning about our biases. Doesn't mean we have to think clever thoughts that no-one else has had before, but simply that we gather information, interpret it, and deliberately form our own conclusions and consequently expand our personal framework of understanding.

It's clear that some WC readers are trying to do this. Changes in media delivery and participatory reporting help, but alone are insufficient as we need to expand our ability to sort and use information wisely and learn from our joint attempts.

Posted by: Janelle on 21 Aug 05

We're already smart enough to deal with climate change.

Huge numbers of people are denying that it's even happening; is that smart?

The available strategies are prevention, amelioration and compensation. It only takes a big enough group to frustrate comprehensive measures to kill the prevention strategy (not very smart), and that's already happened. If we get runaway greenhouse from methane emissions, amelioration will be moot also. Don't ask me how far we can get with compensation, because I don't know.

Intelligence as in "collective IQ" has become very sensitive, flexible and can change dramatically over just a single or a few generations. Much faster than we previously thought. Intelligence has very much become a "nurture" or social matter, and it is not so much an adaptation to changes in natural environments any longer. Evolution's impact on changes in human intelligence has dramatically decreased.

Today's new generations seem to be exponentially smarter than previous ones (that has been established scientifically). The speed with which they assimilate and actively learn to use new technologies and communication strategies shows that new (and 'higher') forms of knowledge and intelligence are emerging as we speak.

Your hypothesis is very interesting: "climate change" is one of those problems that are literally "good to think" -- both global and extremely complex. It forces us to share and to network knowledge, on a global scale, with new tools, concepts and structures, with the participation of a tremendously diverse body of people. Worldchanging is precisely one of the innumerable wheels in this gigantic knowledge network that spans the entire globe and which participates in creating new discourses.

In short, "climate change" has the potential to become a collective intelligence-enhancer first and foremost because it is a "concept", a "discourse" that's being debated by society at large. The actual "physical" threat is much less the trigger here.

I would want to stress the fact that "intelligence" has always been the result of social exchanges and collective enterprises (it's a "discursive formation" - individuals as individuals are irrelevant here; and more so today than ever before; no single person or group of persons can claim to provide "solutions" to such complex, global problems which affect so many different aspects of society - indeed, it transforms intelligence itself, making it more social).
Today only a few basic dimensions of this intelligence-enhancement process have changed: the speed at which the exchange happens, and the (social) space in which it occurs. Both have increased in size tremendously. Global and ultra-complex problems like climate change just take us to yet another level of increasing our collective knowledge and intelligence.

Posted by: Lorenzo on 21 Aug 05

Not to be too much of a bugaboo, but I think the record of extinction supports the idea that modern humans have a poor shot at surviving the climate changes we've set in motion. A species' vulnerability to extinction is related to the flexibility (or adaptability) of their behavior to environmental change. For example, the most endangered of our closest relatives are those who are restricted to tropical forest and cannot adapt to their loss of habitat. At one point in time humans may have been pretty flexible with changes in their environment. Currently however, I think our demands for natural resources make us pretty inflexible. Plus, I don't think 'smarter' (educated) humans are more likely to be flexible with the changes that will occur.

Posted by: Random Primatologist on 21 Aug 05

I don't think 'smarter' (educated) humans are more likely to be flexible...

Ah, but smarter does not equate to educated. The two sometimes coincide, but often do not. In many cases, "educated" can mean close adherence to outdated institutional structures. Up through college, it can mean rote memorization, and in grad school, it can mean sticking close to what faculty advisors are looking for in terms of research and results.

I'm not saying that education is worthless, only that it's possible to become highly educated without having a terribly flexible, adaptable, *intelligent* worldview.

Posted by: Jamais Cascio on 21 Aug 05

Huge numbers of people are denying that it's even happening; is that smart?

E-P, I think you'll find that the "huge numbers" weren't quite as huge as some wanted us to believe, and that they're declining rapidly.

Posted by: Jamais Cascio on 21 Aug 05

When you consider that it only takes a few tens of thousands of scientists and perhaps a million engineers to do the mental heavy lifting and most everyone else just has to follow along, it seems just as likely that those who will "win" are going to be the followers of certain enlightened leaders and intelligence might have very little to do with it.

@engineer_poet.

I think your view of what constitutes "intelligence" is extremely narrow. Intelligence is an entirely social and collective affair, and global problems like climate change stress this fact even more.

Let's not forget who turned "climate change" into a problem in the first place: not just a few scientists, but intellectuals, environmentalists, ideologues, writers, artists, politicians, essayists, even media people and society at large. Engineers came in last (or they haven't yet).

Intelligence is not so much a matter of finding the correct bolt to put it in the right hole, as engineers do. Engineers work at the surface of a deep layer of collectively shared ideas and concepts. If it weren't for the groups of people mentioned above, there wouldn't even be such a discourse about climate change.

That's the whole point Jamais is trying to make, I think (and I hope). Problems like climate change are first and foremost "discourses" and social artifacts, not just problems-to-be-solved by technocrats and engineers.

Lorenzo, that's a more elegant way of saying what I was trying to say.

E-P (and others), I was pretty explicitly *not* arguing that global warming will lead to biological increases in intelligence, so issues of die-offs and genetic selection are moot. Rather, large-scale, large-scope, long-term problems -- global warming being the biggest, but not the only one -- are pushing us towards greater intelligence in terms of both augmentation through tools and social communication & cooperation.

Posted by: Jamais Cascio on 21 Aug 05

We could use a classic game theorist here. He could tell us more about how "collective" intelligence and decision strategies in the face of global and ultra-complex problems like climate change work -- co-operation is definitely the keyword here. And 'transversal' co-operation at that, spanning the most diverse sectors of knowledge production.

Posted by: Lorenzo on 21 Aug 05

The dramatic changes that global warming will make necessary are going to have to be system-wide, society-wide, and deep. The intelligence required is going to be seven generations intelligence and the antithesis to the present late stage monetary capitalistic economic system.

Whether we silly humans are going to be able to change our institutions and cultures quickly enough is debatable. I've seen enough collective stupidity by my own particular species that I have my doubts.

Of course, the end of human beings as a species doesn't mean the end of life on Earth by any means. We're just a pebble on the shore.

All of the above is really getting to the heart of the problems we all face. Reading it suggests to me the following summary, which I do more for my own amusement than any thought of enlightening anyone as smart as all you folks.

1) we are plenty smart enough technically and scientifically to solve problems like global warming. We could do it fast, and it would be fun and profitable, esp. for R&D types like me.
2) But we are not connecting yet. We haven't recognized what all sorts of good people have told us - Buddha, Gandhi, Jesus, and lots of others- that we are all one, and each should be precious to the other, people here, and especially people to come- all alike
3) So what we need is not another Einstein, in fact we have plenty of those, but another M. L. King type, who could speak the words and act the acts that bring us together to enthusiastically do what we all know we have to do and can do right now for te good of all.
4) And in the process, incidentally wipe away the nonsense, like conventional economics, and conventional capitalism, and all the other ism's that say that selfish competition, not cooperation, is good.

Isn't that what World-Changing is all about? Hey, let's do it.
Somebody get up on that stump and start beating the drum.

Here's the slogan--TOGETHER WE CAN.

Posted by: wimbi on 21 Aug 05

There are some interesting comments about evolution here, but it is easy to get confused by the compleity of it all. Here's my understanding, in point form.

1. In some (affluent) situations, humans are not undergoing natural selection. However, there are fairly strong selection pressures in some parts of the world where, for example, Malaria, HIV and getting enough food to live and breed are problems. Natural selection is defiantely occuring in these populations.

1a. Just to add to the mix here, even if natural selection is not happening at present in some populations, there's still stochastic (chance driven) and not-so-stochastic changes in gene frequencies in populations, which will affect evolutionary trajectory once selection pressures reassert themselves.

2. I think that the important distinction between cultural and biological evolution is the timescale that they occur at - my guess is that cultural evolution happens on a scale of days to a couple of hundred years while biological evolution happens much more slowly, particularly in large slow breeding animals like humans.

3. The effect of climate change is going to be different depending on whether it causes catastrophes or not. If it does, and the human population drops a lot and suddenly, the evolutionary consequences will be driven by chance - demographic accident. However, if the changes are gradual then the smarties, or the metabolically frugal or whatever genetically determined traits which are advantageous have a chance can then be selected for, and as pointed out above, per generation increases in fitness can be very small to have significant effects. It's nice to think that smartness might be a source of evolutionary fitness, but it ain't nescessarily going to be the case - those big brains need a lot of energy.

For evolution-in-action, look firstly to the regions of first-and-second-contact at the edges and the population sinkholes called cities in the Third World.

That's where the weak are dying off the fastest.

It's a brutal assessment, but it's accurate.

The First World has also given them new tools such as the computer, the radio, the motorized behicle, etc. All of which is ratchetting the selection process up even more.

And then you have the wars that have recently been thrust upon the weak and the poor.

Part of the question is in fact, what sort of intelligence is being selected for in those circumstances?

Posted by: Wesley Parish on 22 Aug 05

How can a climate change really affect people who live inside climate controlled homes and live in climate controlled houses?

Posted by: James Orman on 22 Aug 05

"How can a climate change really affect people who live inside climate controlled homes and live in climate controlled houses?"

By blowing the roof off the sucker?

"So what we need is not another Einstein, in fact we have plenty of those, but another M. L. King type, who could speak the words and act the acts that bring us together to enthusiastically do what we all know we have to do and can do right now for the good of all."

We don't need one Gandhi or King, we all need to act as if we each were Mohandas or Martin on a daily basis.

This winter is going to be expensive. We can bring the oil war home through energy conservation and efficiency measures, small-scale renewables where affordable, and helping our neighbors and friends organize to do it themselves. This context also allows for the discussion of global warming, market globalization, and ecological design too.

How about a a street art performance with people dressed in WWII-period costumes and signs that promote Conservation for the War Effort. "The homefront save gas and oil for the troops." They could do fuel efficiency check-ups on cars and trucks for free. "(BTW, I believe that we'd be wise to look at the WWII homefront model and study FDR's - and Norman Rockwell's - Four Freedoms as a program for waging peace.)

I say Solar Is Civil Defense and we should get serious about a citizens based civil defense because the Bush administration is certainly not. These days, we need to organize for our own survival, individually, collectively, politically and in fact.

Thanks, gmoke, Two heads are better than one, and two thousand are even better. I really like your idea, and I have some friends who could carry it out in great style. I lived thru WWll and well remember the gas rationing and how nobody griped about it. After all, we were supporting our troops!

Firstly I dont think we can say that natural selection is not occurring in humans. Sure we have dissociated (although we have most certainly not cut the links altogether) ourselves from our natural environment. We are under the forces of natural (biological) selection. The only change that biological evolution has become mixed up with, influenced by and influences social forces - essentially cultural evolution. To try and say that natural selection is only taking place in environmentally pressured societies is to fall into the trap of separating nature and society.

Secondly and reliant on my first point, can we really define intelligence outside of evolution  assuming from the above that it is taking place. For the indicators we use to measure intelligence  because we cannot know it absolutely - must be tied up with the value systems which have been generated through our evolutionary history. Thus if we assume intelligence to be related to our ability to survive (a fair enough assumption given the discussions above) and evolution is the act of survival, should we make it through this current epoch of climate change we will most certainly consider ourselves to be smarter when we are done. Whether we will actually be smarter is a moot point.

Posted by: James on 26 Aug 05

Refute two points -

To say humans are 'evolving' is a misnomer in the traditional sense of the word. Evolution is the impact of fitness on population phenotypes/genotypes. By fitness - biologists imply the ability to reproduce- nothing else. In developed nations Fitness in humans is no longer tied to their environment- there is a disconnect between our ability to reproduce and the environment we live in. It doesn't matter (in the US) if I live in the desert in Nevada, or the wet Pacific Northwest- my ability to reproduce is the same. Our society has enabled us to disconnect, for good and bad from the environment. There are sections of humanity which have utilized society to develop beyond standard evolutionary pressures. We now face new pressures, social pressures, and technological pressures where we have the choice to evolve or not  but it is not defined by our environment- this is the disconnect and why I would say we are no longer evolving in the traditional and literal truth of the word. If you include society/genetics/technology as part of our environment then of course you could say we are evolving but as I said before I believe this is a different beast altogether and behaves under different rules so should not be lumped together.

Secondly, intelligence is difficult to define, I agree. But I would not say that intelligent animals are those that have an ability to survive or have high fitness. Look at a cockroach -by all means of measure we are 'more intelligent' however the cockroach has survived far longer then humans. The evolution of intelligence only occurs when fitness is dependent on an increase in intelligence, and humans do not necessarily need to be more intelligent to reproduce. Indeed it may be that more intelligent humans, aware of their environmental and social responsibilities may choose to be less fit and reproduce less. But there is no evidence for reverse evolution that Im aware of. So, essentially we needed to be intelligent once, so we are intelligent today and we will be at least this intelligent tomorrow- but how it changes is no longer dependent on evolution.